Yeswanth, I'm looking at: https://bitbucket.org/swamiyeswanth/pyti/src/2b3a7401eccf/diskhandler.py from this thread: http://librelist.com/browser//pyti/2011/6/13/disk-handler/ (1) I don't think the code you posted will work unless you move line 23 ('launch') up to just after you've added the drive (after line 12). (2) You probably don't want to use 'add_drive'. This deprecated function has a potential vulnerability, although it will only affect you if you are modifying untrusted raw-format guests. The suggested replacement is 'add_drive_opts' (which also has more features). http://libguestfs.org/guestfs.3.html#guestfs_add_drive http://libguestfs.org/guestfs.3.html#guestfs_add_drive_opts https://bugzilla.redhat.com/642934 (3) Instead of using 'mount', use 'mount_options'. The 'mount' call adds some flags to the mountpoint which are not very useful and also make disk writes very slow. http://libguestfs.org/guestfs.3.html#guestfs_mount http://libguestfs.org/guestfs.3.html#guestfs_mount_options http://libguestfs.org/guestfs.3.html#libguestfs_gotchas (4) After line 33 ('umount_all') you should also call 'self.disk_fs.sync()' which causes the libguestfs drive to be fully synced. Alternatively you can delete the handle ('del self.disk_fs') which assuming no other references are being held will do the same thing. HTH, Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones libguestfs lets you edit virtual machines. Supports shell scripting, bindings from many languages. http://libguestfs.org